JPS6229261Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a structural improvement of a gap adjustment device between a platen and a printing head in a printing device, and its purpose is to easily perform gap adjustment with a simple structure. The goal is to obtain equipment that can do this.

Conventionally, this type of device was developed by Utility Model No. 53-94720.
According to this device, it is necessary to process the shaft for adjusting the gap so that the eccentric positions of both ends of the shaft are the same, which is very time-consuming and , structurally,
Although the gap can only be adjusted, there is no specific gap adjustment mechanism, and it is difficult to determine the gap adjustment reference position, which has the drawback that it requires a lot of effort when adjusting the gap.

The present invention eliminates these drawbacks by fixing the end of the guide shaft at a position offset from a pair of adjustment bushes that are rotatably supported by the frame, and by fixing the end of the guide shaft at a position offset from the pair of adjusting bushes that are rotatably supported by the frame, and A circumferential portion of the adjustment bush engages an adjustment lever fixed to the shaft. A plurality of engaging parts are formed, and the shaft position with respect to the platen is determined based on the relative relationship between the position of the engaging part of the adjustment button and the engaging part formed on the frame, which is set to engage with the adjustment lever in advance. The purpose was achieved by this.

An embodiment of the gap adjustment device according to the present invention will be described in detail with reference to the drawings.

1 to 5 show an embodiment of the gap adjustment device of the present invention, FIG. 1 is a side view of a printing device showing only the main parts of the adjustment device, and FIG. FIG. 3 is a plan view of the device, FIG. 3 is a side view of the other side, FIG. 4 is a cross-sectional view taken along line A-A in FIG. 2, and FIG. 5 is a plan view showing an adjustment button to be described later. Note that the same reference numerals are used for corresponding parts in each figure.

Reference numeral 1 denotes a frame forming a printing device, on which a platen 2 is pivotally supported, and a pair of guide shafts 3 and 4 arranged parallel to the platen 2.

Of the pair of guide shafts, the guide shaft 3 closest to the platen is a perfectly circular bar, and both ends of the shaft are offset from the center of a pair of adjustment bushes 5 rotatably supported on the frame 1. It is fixed in an eccentric hole 5A formed oppositely to each other at the position where it is located. Further, the adjustment bushing 5 is provided with a hole 5B for temporary fixing, so that when the guide shaft 3 and the pair of adjustment bushings 5 are fitted together, the shaft is not twisted relative to the platen 2, so that the shaft is relative to the frame 1. It is designed so that it can be temporarily fixed to the temporary locking portion 1A provided oppositely, for example, with a screw. The other guide shaft 4 is fixed to the frame 1 so as to be parallel to the guide shaft 3.

A carriage 7 on which the print head 6 is mounted and fixed is fitted to the guide shaft 3. The guide shaft 4 and the platen 2 are connected to each other.
The carriage 7 is supported by a notched engaging portion 7A so as to be movable back and forth in a direction perpendicular to the carriage 7, and is driven by a belt 8 from a driving mechanism (not shown).
The print head is driven through the print head 10 so as to face the platen 2, and the print head slides to perform a printing operation.

The adjustment bush 5 has a toothed portion 5C formed in an arc shape centered on the axis of the guide shaft 3.
C is engaged with the claw portion 9A of the adjustment lever 9.
The resilient locking portion 9B of the adjustment lever 9 is engaged with a positioning locking recess 1B formed on the frame to form a second engaging portion. The adjustment lever 9 is screwed onto the guide shaft 3 so as to maintain a preset first engagement part position, and the elastic engagement part 9B engages with the recess 1B provided on the frame. rotated to match.

6 to 8 show the claw portion 9 of the adjustment lever 9.
Each aspect of the first engaging portion position formed by A and the tooth portion 5C of the adjustment bush 5 is shown.

In addition, in order to achieve each of these aspects, as described above, 1
Place the pair of adjustment bushes 5 in a predetermined position, and temporarily fasten the adjustment bushes 5 to the temporary fastening holes 5B and the temporary fastening portions 1A provided on the frame 1 with, for example, screws, and then fix the adjustment lever 9. The position of the first engaging part can be changed by loosening the nut, changing the position of the claw part 9A of the lever, and then screwing it back on.

Specifically, as shown in the adjustment bushing 5 in FIG. 5, the intersection of the dashed-dot lines a and b indicates the center of the adjustment bushing 5 that rotates with respect to the frame 1, and the intersection of the dashed-dotted lines a and c indicates the center of the adjustment bushing 5. The center of the guide shaft 3 on the platen side held by the frame is at an eccentric position with respect to the center of the adjustment bush 5 which rotates with respect to the frame. As the adjustment bushing 5 rotates at a maximum of 90 degrees left and right, the gap can be adjusted within the maximum movement range of the guide shaft 3, which is held by the bushing 5 and moves back and forth with respect to the platen 2. In this embodiment, as shown in FIG.
With the tooth portion 5C of the adjustment bush 5 engaged and set at the center position of the tooth forming range, the adjustment lever locking portion 9B is at the center position of the positioning locking recess 1B formed in the frame 1. It is formed so that it can be rotated 45 degrees to the left and right to position it, taking into consideration the surrounding space. FIG. 6 shows a tooth portion 5 in which the claw portion 9A of the adjustment lever 9 is formed on the adjustment bush 5.
The adjustment range is the rotation angle α ₁ in the position of the adjustment bush 5 shown in FIG. 5, and the adjustment range in FIG. The engagement portion between the claw portion 9A of the lever 9 and the tooth portion 5C formed on the adjustment bushing 5 is shifted to the right rotation position by 45 degrees, and FIG. 8 shows the adjustment lever 9 in the state shown in FIG. 6. The engagement portion between the claw portion 9A and the tooth portion 5C formed on the adjustment bushing 5 is shifted to a 45° left rotation position, and as a result, in the position of the adjustment bushing 5 shown in FIG. In the former case (the embodiment shown in FIG. 7), the gap can be adjusted within the rotation angle α ₂ , and in the latter case (the embodiment shown in FIG. 8 ), the gap can be adjusted within the rotation angle α ₃ . 9th
The figure shows gap adjustment ranges A, B, and C between the platen 2 and print head 6 that can be adjusted corresponding to FIGS. Adjustment button 5 in position mode
, 90°α to the left and right, centering on the dashed line of a.
Assuming that the amount of movement of the guide shaft 3 on the platen side obtained by rotating ₂ and α ₃ , that is, the maximum gap adjustment range of the print head 6 with respect to the platen 2, is l, and that it is assembled with the relationship shown in the figure, Fig. 6 Gap adjustment range A in the embodiment
On the other hand, when set to the embodiment shown in FIG. 7, adjustment can be made within a range _l1 closer to the platen 2, and conversely, when set to the embodiment shown in FIG.
On the other hand, adjustment can be made within the range _l2 on the rear side of the A range. That is, by rotating the adjustment lever 9, the range that can be adjusted by selecting the second engagement part by engaging the locking part 9B of the lever with the recess 1B formed on the frame 1 can be adjusted by one gear. Use the adjustment lever 9 to set the adjustment range as the adjustment range.
The claw portion 9A and the tooth portion 5 formed on the adjustment button 5.
By selecting the first engagement portion according to the engagement position with C, the entire adjustment range can be moved in the front and back direction with respect to the platen 2, so it can be applied to various paper thicknesses, and on the other hand, assembly errors can be reduced. It is possible to easily adjust the gap variation between the platen and the print head when the adjustment lever is set at a predetermined position. In addition, since the space occupied by the rotation range of the adjustment lever 9, the positioning mechanism, etc. can be reduced, a compact printing device can be obtained.Furthermore, there is no need to perform any eccentric processing on the guide shaft, and the relationship with the adjustment bushing can be reduced. Since the purpose can be achieved by matching the guide shaft, there is no need to spend time processing the guide shaft, and with regard to the adjustment bushes, for example, by molding, a large number of the same shape can be obtained, and the adjustment bushes can be easily matched with the guide shafts. There is a practical effect that variations in assembly between the bushings and the like can be eliminated by the relative relationship between the positions of the first and second engaging portions.

In addition, in this embodiment, an optimal embodiment was described in which an adjustment lever is provided on one side, and the first and second engaging portions are also configured by a claw portion, a tooth portion, an elastic member, and a recessed portion. However, even if a plurality of adjustment levers are used or the shapes and combinations of the engaging portions are modified, the gist of the present invention will not be changed.

[Brief explanation of the drawing]

1 to 9 show an embodiment of the gap adjustment device according to the present invention, FIG. 1 is a side view of a printing device showing only the main parts of the adjustment device, and FIG.
3 is a plan view of the printing device in the figure, FIG. 3 is a side view of the other side, FIG. 4 is a sectional view taken along line A-A in FIG. 2, and FIG. 5 is an enlarged plan view of the adjustment button. FIGS. 6 to 8 show each state of engagement between the adjustment lever and the adjustment bush, and FIG. 9 is a schematic diagram showing the gap adjustment range in FIGS. 6 to 8. 1: Frame, 1B: Recessed portion, 5: Adjustment button, 5A: Eccentric hole, 5C: Tooth portion, 9: Adjustment lever, 9A: Claw portion, 9B: Resilient locking portion.

Claims (1)

[Scope of utility model registration request] A pair of guide shafts arranged parallel to the platen holding the printing paper are supported by the frame and are slidably mounted using the shafts as guides,
and a carriage on which the print head is mounted and fixed, and the carriage is rotatably fitted with a guide shaft near the platen of the pair of guide shafts,
In a printing device in which the other guide shaft is supported and formed so as to be movable back and forth in a direction perpendicular to the platen, a pair of adjustment bushes rotatably supported on the frame are placed at an eccentric position on the platen side. The guide shaft has positioning parts for setting both ends of the guide shaft parallel to the platen, and an adjustment lever for rotating the adjustment bush is fixed to the shaft, and
A first lever engaging portion is formed on the circumference of the adjusting bush centered on the guide shaft axis, and has a plurality of engaging portions for setting engagement with the adjusting lever in advance; Further, the frame includes a second lever engaging portion formed with a plurality of engaging portions for positioning the lever as the adjustment lever rotates, and the first lever engaging portion A printing head and a platen, characterized in that a gap adjustment range between the platen and the printing head is set based on the relative positional relationship between a lever engaging part position set in advance at the joint part and the second engaging part position. Gap adjustment device between.